A Series of Lanthanide Chalcogenidogermanates Displaying Two Types of 1-D Polymeric Chains

Abstract

A series of lanthanide chalcogenidogermanates [Ln2(tepa)2(μ-OH)2(μ-Ge2Q6)]n·nH2O {Q = S, Ln = Er (1a), Tm (1b), tepa = tetraethylenepentamine; Q = Se, Ln = Y (1c)} and [Tb2(tepa)2(μ-OH)2(μ-Ge2Se8)]n (2) were prepared under mild solvothermal conditions and structurally characterized. Compounds 1a–c contain 1-D neutral chains [Ln2(tepa)2(μ-OH)2(μ-Ge2Q6)]n based on the linkages of [Ln2(tepa)2(μ-OH)2]4+ cations and [μ-Ge2Q6]4- anions, while compound 2 exhibits another 1-D neutral chain [Tb2(tepa)2(μ-OH)2(μ-Ge2Se8)]n constructed by the combination of [Ln2(tepa)2(μ-OH)2]4+ cations and [μ-Ge2Se8]4- anions with two Se–Se bonds. The 1-D neutral chains of 1a–c are arranged in a crossing manner, but the 1-D neutral chains of 2 are aligned in a parallel manner. Their band gaps in the range of 2.09–3.35 eV are derived from optical absorption spectra.